The present invention relates to elevator systems that employ swinging hatchway doors. In particular, the present invention provides an electromechanical interlock that locks and unlocks a swinging elevator hatchway door and provides a means for determining when the hatchway door is locked.
Elevator systems typically employ hatchway doors and car doors. It is imperative that hatchway doors be locked at all times, unless an elevator car is located at the same landing area as the hatchway door. Moreover, before an elevator car leaves a landing area at which a hatchway door was opened, the elevator system must verify that the hatchway door is locked. Various interlock devices exist for use with sliding hatchway doors, however, there has been heretofore no true electromechanical interlock system (i.e. xe2x80x9ca device that has two related interdependent functions, which are: (a) to prevent the operation of the driving machine by the normal operating device unless the hoistway door is locked in the closed position; and (b) to prevent the opening of the hoistway door from the landing side unless the car is within the landing zone and is either stopped or being stopped.xe2x80x9d (see ASME A-17.1b-1998 incorporated herein by reference)) for swinging hatchway doors.
The present invention provides a true electromechanical interlock for use with swinging hatchway doors that swing between opened and closed positions. In one embodiment, the interlock comprises a pivotal hook that is pivotally mounted on a swinging elevator hatchway door. The pivotal hook is preferably, but not necessarily, mounted on the interior surface (i.e. the shaft, or hoistway, facing surface) of the door. The pivotal hook protrudes in a generally perpendicular direction from the interior surface of the swinging hatchway door. The pivotal hook has a beak end and rotates between a locked and unlocked position. An electrical conductor is mounted on the beak end. A spring or other means biases the pivotal hook toward the locked position. The lug preferably, but not necessarily, has an inclined surface for slidably engaging the beak end when the door swings from the open position to the closed position. The lug also has a locking surface for engaging the beak end when the hook is in the locked position and an attempt to open the door is made. When the pivotal hook is in the locked position, the electrical conductor engages electrical contacts, which may be disposed on an electrical contact assembly, to close an electrical circuit. The closing of the electrical circuit indicates that the pivotal hook is in the locked position and thus, the door is locked closed. A solenoid having an extendable pin is mounted adjacent to the beak end of the pivotal hook so that when the solenoid is energized, the extendable pin extends and contacts the hook, thereby pivoting the pivotal hook from the locked position to the unlocked position. When the solenoid is not energized, the solenoid pin is retracted and the biasing means pivots the pivotal hook to the locked position when the hatchway door is in the closed position. The lug, electrical contact assembly, and solenoid may be mounted on a mounting plate, which in turn can be mounted in an elevator hoistway or on an elevator hatchway door jamb.